(CBS NEWS) -- Doctors in New York have removed a 20-pound tumor from a man's body, saving his life.

The patient, 76-year-old Frank Bollettieri, did not even realize he had the tumor until he had an X-ray after a fall. The basketball-sized growth was a type of soft tissue cancer called a liposarcoma, which is extremely rare, especially this size.

"I honestly didn't think I had a chance at life -- a 20 pound tumor," Bollettieri told CBS News.

Because of the enormous size and weight of the tumor, the man's weight dropped from 185 pounds to 160 pounds after the surgery.

"I think one of the things that surprised us was the size of the tumor," Dr. William Huang, a urologic oncologist at NYU Langone Medical Center, told CBS News. "And what it [the tumor] looked like under imaging, and the lack of symptoms."

When surgeons at NYU Langone Medical Center removed the tumor, they also had to take out one of Bollettieri's kidneys, his spleen and part of his adrenal gland.

"What you don't want to do is tug and pull on something while they are attached to these very delicate blood vessels," said Dr. Joseph Raccuia of NYU Langone Medical Center.

The patient and his family are grateful for his recovery.

"When I got woke up after the operation, I said 'thank you, God'," Bollettieri said.

"For a while I thought I might lose him," said Barbara Bollettieri, Frank's wife.

Doctors say it is likely the tumor could grow back, and therefore Bollettieri is being checked every three months.